Commercial Timbers


H. G. Richter and M. J. Dallwitz

Dipterocarpus spp. (Keruing)

Nomenclature etc. DIPTEROCARPACEAE. D. alatus - Syn. D. incanus Roxb., D. lemeslei Vesque; D. baudii Korth - Syn.: D. duperreana Pierre, D. scortechinii King; D. grandiflorus (Blanco) Blanco - Syn.: D. blancoi Blume, D. griffithii Miq., D. motleyanus Hook.f.; D. kerrii King - Syn.: D. obconicus Foxw., D. perturbinatus Foxw., D. cuneatus Foxw.; D. costulatus v. Slooten; D. verrucosus Foxw. ex v. Slooten. Trade and local names: yang (FR, TH, VN), keruing (ID, MY, DE), gurjun (IN-and, MM, LK), dau (VN, FR), white kanyin, kanyin-byu (MM), chhoeuteal (KH), nhang (LA), keroewing (NL), yang hin, yang na (TH), dzao long (VN). Not protected under CITES regulations.

Tree. Geographic distribution: India, Pakistan, Sri Lanka, Burma, Thailand, Laos, Vietnam, Cambodia, and Indomalesia.

General. Growth ring boundaries distinct. Heartwood basically brown to red brown to yellow brown to green. Sapwood colour distinct from heartwood colour. Density 0.66–0.75–0.8 g/cm³.

Vessels. Wood diffuse-porous. Vessels exclusively solitary. Average tangential vessel diameter 110–210–285 µm. Average number of vessels/mm² 2–3–4. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–7 µm, vestured. Vessel-ray pits with reduced borders or apparently simple, rounded or angular, of uniform size or type and of two distinct sizes or types in the same ray cell, of the same type in adjacent elements and unilaterally compound and coarse. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres of medium wall thickness. Average fibre length 1600–2100–2500 µm. Fibre pits common in both radial and tangential walls, distinctly bordered. Fibres non-septate.

Axial parenchyma. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty and vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–6.

Rays. Rays 5–9 per tangential mm, multiseriate (also if only few), (3–)4–6 cells wide. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows and procumbent, square and upright cells mixed throughout the ray, mostly 2–4 marginal rows of upright or square cells and with more than 4 marginal rows of upright or square cells. Sheath cells absent.

Secretory structures. Intercellular canals present, axial type, diffusely arranged.

Mineral inclusions. Crystals not observed. Silica present, as grains, in rays cells.

Illustrations. • Transverse section. Dipterocarpus coriaceus. Note diffuse axial intercellular canals (IC). IC. IC. IC. • Transverse section. Dipterocarpus alatus. Note diffuse axial intercellular canals (IC). IC. IC. IC. IC. IC. • Tangential section. Dipterocarpus coriaceus. • Radial section. Dipterocarpus coriaceus. • Miscellaneous. Dipterocarpus coriaceus. Note: Large bordered pits in tangential and radial fibre walls. Note: SiO2 particles in ray cells (Si), often concealed by organic contents. Si. Si.

The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.

Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 25th June 2009.’.